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tmpfile(3p) — Linux manual page

TMPFILE(3P)             POSIX Programmer's ManualTMPFILE(3P)

PROLOG        top

       This manual page is part of the POSIX Programmer's Manual.  The       Linux implementation of this interface may differ (consult the       corresponding Linux manual page for details of Linux behavior), or       the interface may not be implemented on Linux.

NAME        top

       tmpfile — create a temporary file

SYNOPSIS        top

       #include <stdio.h>       FILE *tmpfile(void);

DESCRIPTION        top

       The functionality described on this reference page is aligned with       the ISO C standard. Any conflict between the requirements       described here and the ISO C standard is unintentional. This       volume of POSIX.1‐2017 defers to the ISO C standard.       Thetmpfile() function shall create a temporary file and open a       corresponding stream. The file shall be automatically deleted when       all references to the file are closed. The file shall be opened as       infopen() for update (wb+), except that implementations may       restrict the permissions, either by clearing the file mode bits or       setting them to the value S_IRUSR | S_IWUSR.       In some implementations, a permanent file may be left behind if       the process callingtmpfile() is killed while it is processing a       call totmpfile().       An error message may be written to standard error if the stream       cannot be opened.

RETURN VALUE        top

       Upon successful completion,tmpfile() shall return a pointer to       the stream of the file that is created.  Otherwise, it shall       return a null pointer and seterrno to indicate the error.

ERRORS        top

       Thetmpfile() function shall fail if:EINTRA signal was caught duringtmpfile().EMFILEAll file descriptors available to the process are currently              open.EMFILE{STREAM_MAX} streams are currently open in the calling              process.ENFILEThe maximum allowable number of files is currently open in              the system.ENOSPCThe directory or file system which would contain the new              file cannot be expanded.EOVERFLOW              The file is a regular file and the size of the file cannot              be represented correctly in an object of typeoff_t.       Thetmpfile() function may fail if:EMFILE{FOPEN_MAX} streams are currently open in the calling              process.ENOMEMInsufficient storage space is available.The following sections are informative.

EXAMPLES        top

Creating a Temporary File       The following example creates a temporary file for update, and       returns a pointer to a stream for the created file in thefp       variable.           #include <stdio.h>           ...           FILE *fp;           fp = tmpfile ();

APPLICATION USAGE        top

       It should be possible to open at least {TMP_MAX} temporary files       during the lifetime of the program (this limit may be shared withtmpnam()) and there should be no limit on the number       simultaneously open other than this limit and any limit on the       number of open file descriptors or streams ({OPEN_MAX},       {FOPEN_MAX}, {STREAM_MAX}).

RATIONALE        top

       None.

FUTURE DIRECTIONS        top

       None.

SEE ALSO        top

Section 2.5,Standard I/O Streams,fopen(3p),mkdtemp(3p),tmpnam(3p),unlink(3p)       The Base Definitions volume of POSIX.1‐2017,stdio.h(0p)

COPYRIGHT        top

       Portions of this text are reprinted and reproduced in electronic       form from IEEE Std 1003.1-2017, Standard for Information       Technology -- Portable Operating System Interface (POSIX), The       Open Group Base Specifications Issue 7, 2018 Edition, Copyright       (C) 2018 by the Institute of Electrical and Electronics Engineers,       Inc and The Open Group.  In the event of any discrepancy between       this version and the original IEEE and The Open Group Standard,       the original IEEE and The Open Group Standard is the referee       document. The original Standard can be obtained online athttp://www.opengroup.org/unix/online.html .       Any typographical or formatting errors that appear in this page       are most likely to have been introduced during the conversion of       the source files to man page format. To report such errors, seehttps://www.kernel.org/doc/man-pages/reporting_bugs.html .IEEE/The Open Group                2017TMPFILE(3P)

Pages that refer to this page:stdio.h(0p), exit(3p), mkdtemp(3p), stdin(3p), tempnam(3p), tmpnam(3p)

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